Design of reflectarray antenna integrated with FSS textured configurations for wireless communication applications

Modern communication systems require intelligent antenna arrays to achieve increased phase range for the performance improvement. Moreover the design requirements of spacecraft antennas for satellite communications and telecommunication missions require multifunction antennas to prevent the propagation of electromagnetic waves in certain frequency bands. This project investigates the feasibility of employing reflectarray antenna integrated with FSS textured configurations to combat the scan blindness problem. Performance investigation of different strategic resonant elements has been carried out in X-band frequency range by using commercially available computer models of CST MWS and Ansoft HFSS based on Finite Integral Method (FIM) and Finite Element Method (FEM) respectively. Frequency Selective characteristics are also exploited by embedding the dipole, square loop and triangular loop resonant elements on top of the groundless substrate. Integrated FSS Reflectarray (FSS-RA) configurations based on iterative loop length approach are than implemented for operation in both X and Ku-band to improve the static phase range for the reduction of phase errors resulting in scan blindness. It has been demonstrated that the maximum static phase range of 540° can be obtained with the loop length variation of 6.8mm. Moreover novel algorithms based on mathematical models have been developed for the calculation of progressive phase distribution depicted by each individual resonant element and resonant frequency estimation of FSS reflectarrays. In order to validate the authenticity of numerical results waveguide scattering parameter measurements have been carried out by fabricating two patch unit cells for each reflectarray resonant element. Measured results demonstrated that reduction in reflection area of resonant elements from 105.74mm2 to 7.33mm2 tends to increase the reflection loss values from 2.63dB to 20.25dB. Moreover, an increased measured static phase range of 290° offering the reduction in phase errors is also shown by employing the triangular loop element

Resonant cavity antenna arrays: performance investigation and characterization

Empirical thesis.Bibliography: pages 59-64.1. Introduction -- 2. Resonant cavity antennas and recent progress -- 3. RCA element selection for array implementation -- 4. Analytical predictions and array topologies -- 5. Investigation on SLL reduction using a dielectric phase correcting structure -- 6. Scalable planar feeding techniques for array applications -- 7. Conclusions and future work.This thesis investigates the feasibility of developing wideband resonant cavity antennas (RCAs) to achieve ETSI Class-2 antenna requirements for operation in 21.2-23.6 GHz frequency band. Commercially available Class-2 reflector antennas have strict requirements to conform to the suitable radiation pattern envelope (RPE) specifications, as set by the regulatory bodies. Despite excellent performance of commercial Class-2 compliant antennas, a major geometrical constraint prevails due to their non-planar, complex, multi-piece and bulky structures. RCAs on the other hand, are well known for their simple and planar configurations. With rapid advancements in modern wireless technologies, RCAs have found numerous applications from indoor personal communications to wireless sensor networks, and from point-to-point communications to satellite reception. This thesis investigates the possibility of developing wideband and high-gain resonant cavity antenna arrays (RCAAs), to combine the advantages of low-cost, planar configuration with high efficiency and compactness.Mode of access: World wide web1 online resource (xx, 64 pages) colour illustration

Ku-band dielectric resonator antenna array for microwave imaging

In this article, a compact dielectric resonator antenna array was proposed for microwave imaging systems. Four resonator elements of Roger RT/Duroid 6010 were used over the FR4 substrate for an array configuration with a total size of 35 × 50 × 7 mm. The proposed antenna array attained wide operational bandwidth of 6 GHz ranging from 12 to 18 GHz making antenna effectively operational for whole Ku-band. The demonstrated antenna along with being wide-band and small size, possessed essential performance characteristics like appropriate gain, stable radiation patterns, and high radiation efficiency over the entire band, therefore, making proposed antenna a prospective candidate for microwave imaging.5 page(s

Performance Evaluation of Conventional and Planar Feeds in Resonant Cavity Antennas

A simple and planar feeding approach is evaluated for use in wideband Resonant Cavity Antennas (RCAs). Boresight directivity performance of the planar (aperture-coupled dual slot) and a conventional feeding technique (waveguide-fed slot) are investigated by placing each under an unprinted all-dielectric single-layer superstrate with transverse permittivity in lateral dimensions. The well-matched printed feed antenna is shown to achieve a peak directivity of 17 dBi over a wide 3dB directivity bandwidth of 16.2%

A Planar feeding technique for wideband, low-profile resonant cavity antennas

A low profile, wideband resonant cavity antenna (RCA) is presented. It uses a simple and planar wideband feed antenna. The use of this planar, printed feed antenna reduces the overall height of the RCA. The RCA has a single-layer superstrate, which has radially non-uniform permittivity in the transverse plane. Excellent wideband matching was obtained for the RCA with a -10dB return loss bandwidth ranging from 20.81 to 25.32 GHz. Numerical results predict a peak boresight gain of 16.97 dBi. This RCA is well-suited for scalable RCA configurations such as sparse arrays or switched-polarization arrays with printed feed networks.2 page(s

An Efficient Slotted Waveguide Antenna System Integrated with Inside-Grooves and Modified Gaussian Slot Distribution

In this work, an efficient slotted waveguide antenna (SWA) system is designed for S-band high power microwave (HPM) applications. The designed SWA comprises of 10-slot elements placed on the broad wall of SWA with a modified Gaussian distribution (MGD), integrated with two inside-grooves and a Gaussian dielectric radome of high-density polyethylene (HDPE) material. The inside-grooves are introduced to suppress the surface current on the waveguide, which results in high gain as well as sidelobe level (SLL) reduction in the E-plane. The MGD controls the SLLs, and the unique Gaussian profile shape radome offers constant radiation characteristics. The proposed antenna system, within existing size constraints, offers a high gain of 20.1 dBi in conjunction with a high-power handling capability of greater than 100 MW. The designed SWA system has compact dimensions of 8.46λ0 × 1.38λ0 × 1.50λ0, with SLLs of −20 dB and −22 dB in the H- and E-plane, respectively. The HPM antenna system, radiating at 3 GHz, is fabricated on aluminium material using the milling process. The simulated SWA system has good agreement with measured results. Moreover, the proposed SWA system offers clear advantages in terms of its robustness, design simplicity, high power handling capability, and high gain

Generation of Beam Tilt through Three-Dimensional Printed Surface

In this paper, 3D printed surfaces are presented to study this technology’s application in generating beam tilt for the electromagnetic waves in the Ku-band. Additionally, the input source is maintained by a feed horn that is additively manufactured and is coated with copper spray paint to add conductivity, which is fed by a WR-75 waveguide. The proposed beam tilt generating surface is also referred to as a Beam Deviating Surface (BDS). There is no relative gap between the BDS and the aperture of the horn, which eventually decreased the overall antenna height. The BDS layer is able to deviate the beam for a fixed elevation angle of 22.5∘ and could be consequently rotated along with the rotation of the BDS prototype. The voltage standing wave ratio value is less than two over the operating frequency range, which depicts the wideband behavior. The measured and simulated radiation patterns show that we can tilt the electromagnetic waves in ranges of up to +/−22.5∘ with a minimum side lobe level of −5 dB at frequencies from 10 to 15 GHz. This signifies the wideband characteristic of the proposed prototype, which is achieved by Vero material from Multijet Printing that is a low-cost and rapid manufacturing 3D printing technology